Re: [RESEND PATCH bpf-next v6 2/8] bpf: Introduce css_task open-coded iterator kfuncs

[Chuyi Zhou]

Hello,

在 2023/10/30 01:09, Guenter Roeck 写道:
> On Wed, Oct 18, 2023 at 02:17:40PM +0800, Chuyi Zhou wrote:
> > This patch adds kfuncs bpf_iter_css_task_{new,next,destroy} which allow
> > creation and manipulation of struct bpf_iter_css_task in open-coded
> > iterator style. These kfuncs actually wrapps css_task_iter_{start,next,
> > end}. BPF programs can use these kfuncs through bpf_for_each macro for
> > iteration of all tasks under a css.
> >
> > css_task_iter_*() would try to get the global spin-lock *css_set_lock*, so
> > the bpf side has to be careful in where it allows to use this iter.
> > Currently we only allow it in bpf_lsm and bpf iter-s.
> >
> > Signed-off-by: Chuyi Zhou <zhouchuyi@xxxxxxxxxxxxx>
> > Acked-by: Tejun Heo <tj@xxxxxxxxxx>
>
> With this patch in linux-next:
>
> Building m68k:defconfig ... failed
> --------------
> Error log:
> kernel/bpf/task_iter.c: In function 'bpf_iter_css_task_new':
> kernel/bpf/task_iter.c:917:14: error: 'CSS_TASK_ITER_PROCS' undeclared (first use in this function)
>    917 |         case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED:
>        |              ^~~~~~~~~~~~~~~~~~~
> kernel/bpf/task_iter.c:917:14: note: each undeclared identifier is reported only once for each function it appears in
> kernel/bpf/task_iter.c:917:36: error: 'CSS_TASK_ITER_THREADED' undeclared (first use in this function)
>    917 |         case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED:
>
> My apologies for the noise if this has already been reported and/or fixed.
>
> Guenter

Here is the previous discussion link:
https://lore.kernel.org/lkml/20231020132749.1398012-1-arnd@xxxxxxxxxx/

We can talk this issue on that maillist.

thanks.